The present invention relates to protein materials used as fat or cream substitutes. In particular, concentrated, substantially non-aggregated, casein micelles are employed as fat substitutes and can replace all or a portion of fat or cream in fat/cream containing foods having a pH greater than about 5.6. Additionally, the present invention relates to a method reducing the fat content of these foods and compositions containing concentrated casein micelles as a fat substitute.
Casein micelles are naturally occurring proteinaceous microparticles found in milk and contribute to the turbidity or white color of milk. They generally have a spheroidal shape and a diameter of from about 0.1 to 0.4 microns (.mu.). Casein is employed as a stabilizing agent for fat emulsions. Casein micelles are pH sensitive and coagulate at a pH under about 5.1 to form cheese. Skim milk contains casein in an amount of about 3.2% by weight of which 80-97% are in the micellar form. (See Fundamentals of Dairy Chemistry, 2nd Edition, Webb et al., eds., The AVI Publishing Co., Inc., Westport, CT., page 607, 1974.) Skim milk also contains about 4.8% by weight lactose (about 52% by weight of the milk solids). In frozen dairy products, such as ice cream, lactose is undesirable in concentrations greater than about 6% because it crystallizes and contributes a sandy mouthfeel.
U.S. Pat. No. 4,631,196 to Zeller discloses non-fat dairy products containing (1) water, (2) skim milk or cultured skim milk, (3) a mixture of polydextrose and sucrose, (4) milk solids, and (5) stabilizers/emulsifiers.
U.S. Pat. No. 4,689,245 to Kosikowski et al. discloses a low-fat dairy coffee whitener. The coffee whitener is made from (1) decreamed milk ultrafiltration retentate having its protein concentrated between 2:1 to 4:1 compared to the protein content of the starting milk, and (2) riboflavin and/or beta carotene as a whitening enhancer.
U.S. Pat. No. 4,734,287 to Singer et al. discloses a proteinaceous, water dispersible macrocolloid having a smooth, emulsion-like organoleptic character when hydrated. The macrocolloid comprises substantially non-aggregated particles of denatured dairy whey protein having a mean diameter particle size distribution in a dried state ranging from 0.1.mu.-2.0.mu. with less than about 2 percent of the total number of particles exceeding 3.0.mu. in diameter. Singer et al. employ the denatured dairy whey macrocolloid as a fat substitute.
It has been unexpectedly discovered that concentrated, substantially non-aggregated, casein micelles can act as a fat substitute.